package com.item.news.util;

import java.io.UnsupportedEncodingException;

public class ChangeCharset {
 /** 7位ASCII字符，也叫作ISO646-US、Unicode字符集的基本拉丁块 */  
 public static final String US_ASCII = "US-ASCII";  
  
 /** ISO 拉丁字母表 No.1，也叫作 ISO-LATIN-1 */  
 public static final String ISO_8859_1 = "ISO-8859-1";  
  
 /** 8 位 UCS 转换格式 */  
 public static final String UTF_8 = "UTF-8";  
  
 /** 16 位 UCS 转换格式，Big Endian（最低地址存放高位字节）字节顺序 */  
 public static final String UTF_16BE = "UTF-16BE";  
  
 /** 16 位 UCS 转换格式，Little-endian（最高地址存放低位字节）字节顺序 */  
 public static final String UTF_16LE = "UTF-16LE";  
  
 /** 16 位 UCS 转换格式，字节顺序由可选的字节顺序标记来标识 */  
 public static final String UTF_16 = "UTF-16";  
  
 /** 中文超大字符集 */  
 public static final String GBK = "GBK";  
  
 /** 
  * 将字符编码转换成US-ASCII码 
  */  
 public String toASCII(String str) throws UnsupportedEncodingException {
  return this.changeCharset(str, US_ASCII);  
 }  
 /** 
  * 将字符编码转换成ISO-8859-1码 
  */  
 public String toISO_8859_1(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, ISO_8859_1);  
 }  
 /** 
  * 将字符编码转换成UTF-8码 
  */  
 public String toUTF_8(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, UTF_8);  
 }  
 /** 
  * 将字符编码转换成UTF-16BE码 
  */  
 public String toUTF_16BE(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, UTF_16BE);  
 }  
 /** 
  * 将字符编码转换成UTF-16LE码 
  */  
 public String toUTF_16LE(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, UTF_16LE);  
 }  
 /** 
  * 将字符编码转换成UTF-16码 
  */  
 public String toUTF_16(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, UTF_16);  
 }  
 /** 
  * 将字符编码转换成GBK码 
  */  
 public String toGBK(String str) throws UnsupportedEncodingException{  
  return this.changeCharset(str, GBK);  
 }  
   
 /** 
  * 字符串编码转换的实现方法 
  * @param str  待转换编码的字符串 
  * @param newCharset 目标编码 
  * @return 
  * @throws UnsupportedEncodingException 
  */  
 public static String changeCharset(String str, String newCharset)
   throws UnsupportedEncodingException {  
  if (str != null) {  
   //用默认字符编码解码字符串。  
   byte[] bs = str.getBytes();  
   //用新的字符编码生成字符串  
   return new String(bs, newCharset);  
  }  
  return null;  
 }  
 /** 
  * 字符串编码转换的实现方法 
  * @param str  待转换编码的字符串 
  * @param oldCharset 原编码 
  * @param newCharset 目标编码 
  * @return 
  * @throws UnsupportedEncodingException 
  */  
 public String changeCharset(String str, String oldCharset, String newCharset)  
   throws UnsupportedEncodingException {  
  if (str != null) {  
   //用旧的字符编码解码字符串。解码可能会出现异常。  
   byte[] bs = str.getBytes(oldCharset);  
   //用新的字符编码生成字符串  
   return new String(bs, newCharset);  
  }  
  return null;  
 }  
  
 public static void main(String[] args) throws UnsupportedEncodingException {  
  ChangeCharset test = new ChangeCharset();  
  String str = "This is a 中文的 String!";  
  System.out.println("str: " + str);  
  String gbk = test.toGBK(str);  
  System.out.println("转换成GBK码: " + gbk);  
  System.out.println();  
  String ascii = test.toASCII(str);  
  System.out.println("转换成US-ASCII码: " + ascii);  
  gbk = test.changeCharset(ascii,ChangeCharset.US_ASCII, ChangeCharset.GBK);  
  System.out.println("再把ASCII码的字符串转换成GBK码: " + gbk);  
  System.out.println();  
  String iso88591 = test.toISO_8859_1(str);  
  System.out.println("转换成ISO-8859-1码: " + iso88591);  
  gbk = test.changeCharset(iso88591,ChangeCharset.ISO_8859_1, ChangeCharset.GBK);  
  System.out.println("再把ISO-8859-1码的字符串转换成GBK码: " + gbk);  
  System.out.println();  
  String utf8 = test.toUTF_8(str);  
  System.out.println("转换成UTF-8码: " + utf8);  
  gbk = test.changeCharset(utf8,ChangeCharset.UTF_8, ChangeCharset.GBK);  
  System.out.println("再把UTF-8码的字符串转换成GBK码: " + gbk);  
  System.out.println();  
  String utf16be = test.toUTF_16BE(str);  
  System.out.println("转换成UTF-16BE码:" + utf16be);  
  gbk = test.changeCharset(utf16be,ChangeCharset.UTF_16BE, ChangeCharset.GBK);  
  System.out.println("再把UTF-16BE码的字符串转换成GBK码: " + gbk);  
  System.out.println();  
  String utf16le = test.toUTF_16LE(str);  
  System.out.println("转换成UTF-16LE码:" + utf16le);  
  gbk = test.changeCharset(utf16le,ChangeCharset.UTF_16LE, ChangeCharset.GBK);  
  System.out.println("再把UTF-16LE码的字符串转换成GBK码: " + gbk);  
  System.out.println();  
  String utf16 = test.toUTF_16(str);  
  System.out.println("转换成UTF-16码:" + utf16);  
  gbk = test.changeCharset(utf16,ChangeCharset.UTF_16LE, ChangeCharset.GBK);  
  System.out.println("再把UTF-16码的字符串转换成GBK码: " + gbk);  
  String s = new String("中文".getBytes("UTF-8"),"UTF-8");  
  System.out.println(s);  
 }  
}  
   

